Centrifugal pumps with slip-coupling



Feb. 28, 1967 s. ENGLESSON 3,306,219

CENTRIFUGAL PUMPS WITH SLIP-COUPLING (CLUTCH) Filed Dec. 14, 1964 2 Sheets$heet 1 H 1/ 9 V I0 l3 ,3 8 IIQ I' INVENTOR: flak W Feb. 28, 1967 s. ENGLESSON 3,306,219

CENTRIFUGAL PUMPS WITH SLIP-COUPLING (CLUTCH) Filed Dec. 14, 1964 2 Sheets-Sheet 2 INVENTOE: SNTEN ENGLESSON,

By M fl 4 H\$ ATTORNEY.

United States Patent CENTRIFUGAL PUMPS WITH SLIP-COUPLING (CLUTCH) Sixten Englesson, Djursholm, Sweden, assignor of onehalf to AB Flygts Pumpar, Solna, Sweden Filed Dec. 14, 1964, Ser. No. 418,083

Claims priority, application Sweden, Dec. 16, 1963,

13,955 63 4 Claims. (Cl. 103-87) The present invention relates to the control of the capacity and discharge head in centrifugal pumps.

Such control can be achieved in various ways, the most economical being, with regard to the required power of the pump, to increase or reduce the number of revolutions of the pump. Variations of the speed of the pump can be achieved by means of a variable driving motor, a constant speed driving motor combined with a variable gearing, and by means of a driving motor having a constant number of revolutions and a slip-coupling connected to the centrifugal pump.

To a certain degree the latter adaption gives a control of lower efliciency than, for example, a mechanical gearing, but it has the substantial advantage of being inexpensive. Furthermore, on comparison with throttle-control, i.e., control by means of a valve, it is, to a considerable degree, more economic.

Control by slippage, however, gives a loss proportional to the difference in revolutions which is converted into heat which must be dissipated by cooling.

Thus the invention relates to a centrifugal pump which includes an impeller arranged in a fluid reservoir for the pumped fluid and a driving motor for the impeller, said motor being arranged outside the pumped fluid. The distinguishing feature of the invention being that the impeller is coupled via a slip-coupling arranged in said fluid-reservoir to its driving motor. Thereby heat losses are given directly to the pumped fluid and a compact construction is obtained which requires little space. According to the invention the slip-coupling may suitably be constructed of a hydrostatic coupling besides which the impeller may, to advantage, be equipped with cooling flanges.

The invention will subsequently be described in detail with references to the attached drawing wherein:

FIG. 1 is a sectional view of a centrifugal pump arranged according to the invention;

FIG. 2 is a fragmentary sectional view similar to FIG. 1 but showing a modification; and

FIG. 3 is a fragmentary sectional view showing a further modification.

The reference numeral 1 on the drawing indicates the inlet to the pump housing 2 in which the impeller 3 is arranged. The stator of the electrical driving motor of the pump is indicated by the numeral 4, and the rotor of the motor by the numeral 5. The shafts 6 of the driving motor is hollow and enters into a socket shaped shaft 7 on a slip-coupling that has a casing 8 (FIGS. 1, 2; or 28, FIG. 3) which, according to the invention, is secured directly to the impeller 3 (FIGS. 1, 3; or 33, FIG. 2) and is arranged within that section of the pump through which the pumped fluid passes. The socket shaped shaft 7 is guided by a bearing 12 and pumping section of the pump and its driving section is eflected by means of a seal 13.

sealing between the fluid The shaft of the pump is mounted in an axial-radial bearing 9, and a regulation pin 10 is passed therethrough which is capable of being influenced by a regulating mechanism 11 and which, in its turn, can actuate the slip-coupling 8 in such a way that different degrees of slip of the impeller are obtained. This can be achieved, for example, by allowing the regulating pin to actuate a throttle valve between the suction and pressure sides of a hydrostatic coupling, preferably constructed as a gear pump.

The control-mechanism 11 can, e.g., include an electric motor controlled by a thermostat or the like. Finally, the discharge opening of the pump is indicated by the reference numeral 14.

Through the method of construction of the pump one obtains the considerable advantage of a much more effective cooling of the coupling than in usual cases, firstly because the impeller 8, 28, which already serves in itself as a cooling means, can be supplied with cooling-flanges 15 (see FIG. 2) and thereby given an increased cooling area, and secondly because the coupling is enclosed in the pumped fluid which thus serves as a cooling medium. Furthermore, a pump is obtained which is more compact than has previously been the case. The casing 8, 28 of the slip-coupling can also be suitably supplied with cooling-flanges 16 (see FIG. 3).

In heat conductive pumps constructed according to the invention a further advantage obtained is that the frictionheat is transferred to the pumped water and thus gives it additional heat.

The construction according to the invention can, to advantage, be used with blowers, especially high pressure blowers.

The invention is thus not limited to the embodiment described above or as illustrated in the drawing, which constitutes only one example of the invention and its application.

What I claim is:

1. A centrifugal pump including a fluid pumping chamber and an impeller arranged in said fluid pumping chamber for the pumped fluid, and a driving motor for said impeller arranged outside the pumped fluid, a hydraulic slip-coupling adjustably connecting said impeller to its driving motor, said slip-coupling being arranged in said fluid pumping chamber, said slip-coupling and impeller being thereby operable to impart the occurring heat to said fluid.

2. A centrifugal pump, as claimed in claim 1, in which the hydraulic slip-coupling is constituted by a hydrostatic coupling.

3. A centrifugal pump, as claimed in claim 1, in which the impeller is provided with cooling flanges.

4. A centrifugal pump, as claimed in claim 1, in which the casing of the hydraulic slip-coupling is provided with cooling flanges.

References Cited by the Examiner UNITED STATES PATENTS 2,441,855 5/1948 Trumpler 230-11 2,500,002 3/1950 Miller 103115 X 2,970,548 2/1961 Berner 10387 ROBERT M. WALKER, Primary Examiner. 

1. A CENTRIFUGAL PUMP INCLUDING A FLUID PUMPING CHAMBER AND AN IMPELLER ARRANGED IN SAID FLUID PUMPING CHAMBER FOR THE PUMPED FLUID, AND A DRIVING MOTOR FOR SAID IMPELLER ARRANGED OUTSIDE THE PUMPED FLUID, A HYDRAULIC SLIP-COUPLING ADJUSTABLY CONNECTING SAID IMPELLER TO ITS DRIVING MOTOR, SAID SLIP-COUPLING BEING ARRANGED IN SAID FLUID PUMPING CHAMBER, SAID SLIP-COUPLING AND IMPELLER BEING THEREBY OPERABLE TO IMPART THE OCCURRING HEAT TO SAID FLUID. 